TiC-and Ti(C,N)-based cermets are excellent in semi-and final finishing of work piece during cutting operations. Typical microstructure of the cermets is a core/rim structure. The undissolved Ti(C,N) cores contribute to their high hardness while the rim phases, (Ti,M1,M2)(C,N)-type solid solutions, play great roles in enhancing the toughness. In this paper, various ultrafine pre-mixed MeC-Ni powders were synthesized and the powders were sintered or hot pressed after mixing in order to control the size and volume fractions of core and rim phases in the system. This paper will present the factors determining the microstructure along with mechanical properties.

본 연구에서는 Metal 환자를 대상으로 자기공명영상검사를 할 때 발생할 수 있는 자화율 인공물을 줄이 기 위해 SEMAC(Slice Encoding for Metal Artifact Correction) 기법을 사용하여 실험하였다. 실험도구는 신체 조직과 유사한 Foot&Ankle Phantom을 사용하였으며 자화율 인공물을 만들기 위해 3.8 cm의 일반 나사못을 사용하였다. 실험장비는 3.0T Magnetom Skyra를 이용하였으며, 얻어진 영상에서는 신호 꺼짐 현상이 가장 두드러지는 17번째 영상으로 면적을 측정하였다. 분석방법은 동일한 부위에서의 신호 꺼짐 현상의 면적을 측정한 후에 통계프로그램인 SPSS(Ver.25)를 사용하여 평균을 구한 후 Wilcoxon 부호순위검정(Signed Rank Test)으로 유의성을 평가하였다. 연구결과 Non SEMAC일 때의 면적은 289.5300±23.07197 mm로 신호 꺼짐 현상이 가장 크게 나타났으며 SEMAC 사용 후 Turbo Factor를 3, 4, 5로 변화를 주었을 때 각각 125.0200±7. 45875 mm, 120.9600±12.01704 mm, 108.7900±16.53498 mm로 감소하였다. 결론적으로 본 연구는 SEMAC 사용 시 자화율 인공물을 효과적으로 감소시켜 SEMAC의 유의성을 증명하였고 TF를 함께 적용하였을 때 촬영시간 감소와 인공물의 면적을 효과적으로 줄일 수 있음을 보여준다.

Genomic DNAs were extracted from the turtle leg (Pollicipes mitella, 1798) population of Tongyeong, Yeosu and Manjaedo located in the southern sea of Korea. The turtle leg population from Tongyeong (0.929) exhibited higher bandsharing values than did turtle leg from Manjaedo (0.852). The higher fragment sizes (>1,200 bp) are much more observed in the Yeosu population. The number of unique loci to each population and number of shared loci by the three populations, generated by PCR using 7 primers in the turtle leg (P. mitella) population of Tongyeong, Yeosu and Manjaedo. Genetic distances among different individuals of the Tongyeong population of the turtle leg (lane 1－07), Yeosu population of the turtle leg (lane 08－14) and Manjaedo population of the turtle leg (lane 15－21), respectively, were generated using the CLASSIFICATION option in Systat version 10 according to the bandsharing values and similarity matrix. The dendrogram, obtained by the seven decamer primers, indicated three genetic clusters: cluster 1 (TONGYEONG 01－TONGYEONG 07), cluster 2 (YEOSU 08－YEOSU 14), and cluster 3 (MANJEDO 15－MANJEDO 21). Tongyeong population could be evidently discriminated with the other two Yeosu and Manjaedo populations among three populations. The longest genetic distance (0.305) was found to exist between individuals’ no. 02 of the Tongyeong population and no. 13 of the Yeosu population. It seems to the authors that this is a result of a high degree of inbreeding in narrow region for a long while.

Off-line ship chartering is done nearly through the brokers. Because of the international scale of chartering market, brokers spend too much times and costs on searching the most appropriate product which the consumers want. In this research, we propose the on-line Charter Product Categorization Model to search the products efficiently in the Cyber Chartering System. This Model will make concerned parties of the ship chartering to get unified product information efficiently, and the select the most appropriate product. In this research, we classified the ship chartering products into categories of cargo, ship type, and sea routes, and defined mutual relation of each products, and we verified that this classification is necessary to search the products through the product searching experiment.